I'm traveling to Chile next week and need to confirm that 24-105mm plus the 40mm on my 5DMK3 will do the trick for Santiago and 100 miles around it. We are not going to the mountains but will head to a ranch in Curacavi.

I have plenty of other lenses including the 24-70 II, 35mm f/1.4, 17-40mm and 70-200mm f/4 IS among my other choices. I excluded other portrait primes from the list.

It is summer in Chile so the days are longer and outdoor light will be good. 24mm should be wide enough to capture architecture for Santiago and Valparaiso. For challenging indoors, I'm thinking the 40mm, IS of 24-105mm and ISO of 5DMK3 are options.

I don't want to travel with a lot of camera gear so I'm thinking this is manageable weight in my messenger bag.

I would (and did) take the 35L instead of the 40. One stop better without IS is not a reason good enough to take the 40, IMO. On the other hand, the 35L did a fine job in Belavista at night.

Go to Valparaiso, and join some group or hire a guide. You will miss half of the places without a guide. Valparaiso is a photographer's paradise. Santiago is safe in general but in Valparaiso, keep your camera in the bag unless you need to take a shot. The wineries around Santiago are very nice. You can hire a taxi for a whole day for a fixed price - not cheap but convenient.

My brief experience with the mountains at 1-2 hour drive from Santiago was not positive.

I think I'd consider your 70-200 along with the 24-1105. There might be a few times you'd want the reach, especially if any interesting critters show up outside the city. You can carry the camera with the 24-105 attached and keep the 70-200 in the bag as well. The 40 can literally go in you pocket.

I would (and did) take the 35L instead of the 40. One stop better without IS is not a reason good enough to take the 40, IMO. On the other hand, the 35L did a fine job in Belavista at night.

Go to Valparaiso, and join some group or hire a guide. You will miss half of the places without a guide. Valparaiso is a photographer's paradise. Santiago is safe in general but in Valparaiso, keep your camera in the bag unless you need to take a shot. The wineries around Santiago are very nice. You can hire a taxi for a whole day for a fixed price - not cheap but convenient.

My brief experience with the mountains at 1-2 hour drive from Santiago was not positive.

I'll be with my girlfriend's family who are Chilean. They did say they will take us to some wineries.

There's no question that my 24-105 is my most-used travel lens. But, I bring something wider for some building interiors and, depending on the destination, something longer for those times I'd want / need it.

So, my present travel kit is usually gonna be the 17-40, 24-105, and one of the 70-200's with or without a TC. This fits nicely into my Retrospective bag and I can comfortably carry this all day.